The present invention relates to methods for selecting a patient responsive to a headache treatment and to methods for treating a headache. In particular, the present invention relates to methods for selecting a patient responsive to treatment of a headache with a botulinum toxin and to methods for treating a headache with a botulinum toxin.
A headache is a pain in the head, such as in the scalp, face, forehead or neck. A headache can be a primary headache or a secondary headache. A primary headache is a headache that is not caused by another condition. Contrarily, a secondary headache is due to a disease or medical condition, such as an illness, infection, injury, stroke or other abnormality. Thus, with a secondary headache there is an underlying disorder that produces the headache as a symptom of that underlying disorder. Tension headache is the most common type of primary headache and tension headaches account for about 90% of all headaches. A tension headache is often experienced in the forehead, in the back of the head and neck, or in both regions. It has been described as a tight feeling, as if the head were in a vise. Soreness in the shoulders or neck is common. Nausea is uncommon with a tension headache.
Migraine headaches are recurrent headaches that may be unilateral or bilateral. Migraine headaches may occur with or without a prodrome. The aura of a migraine may consist of neurologic symptoms, such as dizziness, tinnitus, scotomas, photophobia, or visual scintillations (eg, bright zigzag lines). Migraines without aura are the most common, accounting for more than 80% of all migraines.
An estimated 10-20% of the population suffers from migraine headaches. An estimated 6% of men and 15-17% of women in the United States have migraine. Migraines most commonly are found in women, with a 3:1 female-to-male ratio.
About 2% of all headaches are secondary headaches. For example, a cervicogenic headache is a headache which is due to a neck problem, such as an abnormality of neck muscles, which can result from prolonged poor posture, arthritis, injuries of the upper spine, or from a cervical spine disorder. Sinus headache is another type of secondary headache. A sinus headache can be caused by inflammation and/or infection in the paranasal sinuses.
An ocular headache (i.e. opthalmoplegic migraine) presents with a lateralized pain (often around the eye) often accompanied by nausea, vomiting, and double vision. With ocular headache visual disturbances are common and can include visual hallucinations, such as sparks, light flashes, zigzags of light or visual field defects. The patient can report pain or pressure on or in his eyes. An ocular headache pain is a pain which is localized in or around the eye.
A headache (such as a migraine headache) can be accompanied by an exploding headache pain. An exploding headache pain has the seminal diagnostic characteristic of perception by the patient of a pressure or force being exerted within the skull (that is within the head) in an outward fashion. The patient can report that it feels as if his head is going to explode, as if his head will split open, and/or that it feels as if someone is stabbing him inside his head. Thus, in an exploding headache the pain is perceived by the patient as a type of pain that moves from the inside to the outside of the head. Contrarily, a headache (such as a migraine headache) can be accompanied by an imploding headache pain. An imploding headache pain has the seminal diagnostic characteristic of perception by the patient of a pressure or force being exerted from outside of the skull in an inward fashion. The patient can report that it feels as if something heavy is sitting on his head (such as on his forehead), as if something is squeezing his head, as if something is tightening a vice on his head, and/or as if a sharp object is being inserted into his head. Thus, in an imploding headache the pain is perceived by the patient as a type of pain that moves from the outside to the inside of the head.
Botulinum Toxin
The genus Clostridium includes more than one hundred and twenty seven species, grouped according to their morphology and functions. The anaerobic, gram positive bacterium Clostridium botulinum produces a potent polypeptide neurotoxin, botulinum toxin, which causes a neuroparalytic illness in humans and animals referred to as botulism. The spores of Clostridium botulinum are found in soil and can grow in improperly sterilized and sealed food containers of home based canneries, which are the cause of many of the cases of botulism. The effects of botulism typically appear 18 to 36 hours after eating the foodstuffs infected with a Clostridium botulinum culture or spores. The botulinum toxin can apparently pass unattenuated through the lining of the gut and attack peripheral motor neurons. Symptoms of botulinum toxin intoxication can progress from difficulty walking, swallowing, and speaking to paralysis of the respiratory muscles and death.
Botulinum toxin type A is the most lethal natural biological agent known to man. About 50 picograms of a commercially available botulinum toxin type A (purified neurotoxin complex)1 is a LD50 in mice (i.e. 1 unit). One unit of BOTOX® contains about 50 picograms (about 56 attomoles) of botulinum toxin type A complex. Interestingly, on a molar basis, botulinum toxin type A is about 1.8 billion times more lethal than diphtheria, about 600 million times more lethal than sodium cyanide, about 30 million times more lethal than cobra toxin and about 12 million times more lethal than cholera. Singh, Critical Aspects of Bacterial Protein Toxins, pages 63-84 (chapter 4) of Natural Toxins II, edited by B. R. Singh et al., Plenum Press, New York (1976) (where the stated LD50 of botulinum toxin type A of 0.3 ng equals 1 U is corrected for the fact that about 0.05 ng of BOTOX® equals 1 unit). One unit (U) of botulinum toxin is defined as the LD50 upon intraperitoneal injection into female Swiss Webster mice weighing 18 to 20 grams each. 1Available from Allergan, Inc., of Irvine, Calif. under the tradename BOTOX® in 100 unit vials)
Seven generally immunologically distinct botulinum neurotoxins have been characterized, these being respectively botulinum neurotoxin serotypes A, B, C1, D, E, F and G each of which is distinguished by neutralization with type-specific antibodies. The different serotypes of botulinum toxin vary in the animal species that they affect and in the severity and duration of the paralysis they evoke. For example, it has been determined that botulinum toxin type A is 500 times more potent, as measured by the rate of paralysis produced in the rat, than is botulinum toxin type B. Additionally, botulinum toxin type B has been determined to be non-toxic in primates at a dose of 480 U/kg which is about 12 times the primate LD50 for botulinum toxin type A. Moyer E et al., Botulinum Toxin Type B: Experimental and Clinical Experience, being chapter 6, pages 71-85 of “Therapy With Botulinum Toxin”, edited by Jankovic, J. et al. (1994), Marcel Dekker, Inc. Botulinum toxin apparently binds with high affinity to cholinergic motor neurons, is translocated into the neuron and blocks the release of acetylcholine. Additional uptake can take place through low affinity receptors, as well as by phagocytosis and pinocytosis.
Regardless of serotype, the molecular mechanism of toxin intoxication appears to be similar and to involve at least three steps or stages. In the first step of the process, the toxin binds to the presynaptic membrane of the target neuron through a specific interaction between the heavy chain, H chain, and a cell surface receptor; the receptor is thought to be different for each type of botulinum toxin and for tetanus toxin. The carboxyl end segment of the H chain, HC, appears to be important for targeting of the toxin to the cell surface.
In the second step, the toxin crosses the plasma membrane of the poisoned cell. The toxin is first engulfed by the cell through receptor-mediated endocytosis, and an endosome containing the toxin is formed. The toxin then escapes the endosome into the cytoplasm of the cell. This step is thought to be mediated by the amino end segment of the H chain, HN, which triggers a conformational change of the toxin in response to a pH of about 5.5 or lower. Endosomes are known to possess a proton pump which decreases intra-endosomal pH. The conformational shift exposes hydrophobic residues in the toxin, which permits the toxin to embed itself in the endosomal membrane. The toxin (or at a minimum the light chain) then translocates through the endosomal membrane into the cytoplasm.
The last step of the mechanism of botulinum toxin activity appears to involve reduction of the disulfide bond joining the heavy chain, H chain, and the light chain, L chain. The entire toxic activity of botulinum and tetanus toxins is contained in the L chain of the holotoxin; the L chain is a zinc (Zn++) endopeptidase which selectively cleaves proteins essential for recognition and docking of neurotransmitter-containing vesicles with the cytoplasmic surface of the plasma membrane, and fusion of the vesicles with the plasma membrane. Tetanus neurotoxin, botulinum toxin types B, D, F, and G cause degradation of synaptobrevin (also called vesicle-associated membrane protein (VAMP)), a synaptosomal membrane protein. Most of the VAMP present at the cytoplasmic surface of the synaptic vesicle is removed as a result of any one of these cleavage events. Botulinum toxin serotype A and E cleave SNAP-25. Botulinum toxin serotype C1 was originally thought to cleave syntaxin, but was found to cleave syntaxin and SNAP-25. Each of the botulinum toxins specifically cleaves a different bond, except botulinum toxin type B (and tetanus toxin) which cleave the same bond. Each of these cleavages block the process of vesicle-membrane docking, thereby preventing exocytosis of vesicle content.
Botulinum toxins have been used in clinical settings for the treatment of neuromuscular disorders characterized by hyperactive skeletal muscles (i.e. motor disorders). In 1989 a botulinum toxin type A complex has been approved by the U.S. Food and Drug Administration for the treatment of blepharospasm, strabismus and hemifacial spasm. Subsequently, a botulinum toxin type A was also approved by the FDA for the treatment of cervical dystonia and for the treatment of glabellar lines, and a botulinum toxin type B was approved for the treatment of cervical dystonia. Non-type A botulinum toxin serotypes apparently have a lower potency and/or a shorter duration of activity as compared to botulinum toxin type A. Clinical effects of peripheral intramuscular botulinum toxin type A are usually seen within one week of injection. The typical duration of symptomatic relief from a single intramuscular injection of botulinum toxin type A averages about three months, although significantly longer periods of therapeutic activity have been reported.
Although all the botulinum toxins serotypes apparently inhibit release of the neurotransmitter acetylcholine at the neuromuscular junction, they do so by affecting different neurosecretory proteins and/or cleaving these proteins at different sites. For example, botulinum types A and E both cleave the 25 kiloDalton (kD) synaptosomal associated protein (SNAP-25), but they target different amino acid sequences within this protein. Botulinum toxin types B, D, F and G act on vesicle-associated protein (VAMP, also called synaptobrevin), with each serotype cleaving the protein at a different site. Finally, botulinum toxin type C1 has been shown to cleave both syntaxin and SNAP-25. These differences in mechanism of action may affect the relative potency and/or duration of action of the various botulinum toxin serotypes. Apparently, a substrate for a botulinum toxin can be found in a variety of different cell types. See e.g. Biochem J 1; 339 (pt 1):159-65:1999, and Mov Disord, 10(3):376:1995 (pancreatic islet B cells contains at least SNAP-25 and synaptobrevin).
The molecular weight of the botulinum toxin protein molecule, for all seven of the known botulinum toxin serotypes, is about 150 kD. Interestingly, the botulinum toxins are released by Clostridial bacterium as complexes comprising the 150 kD botulinum toxin protein molecule along with associated non-toxin proteins. Thus, the botulinum toxin type A complex can be produced by Clostridial bacterium as 900 kD, 500 kD and 300 kD forms. Botulinum toxin types B and C1 is apparently produced as only a 700 kD or 500 kD complex. Botulinum toxin type D is produced as both 300 kD and 500 kD complexes. Finally, botulinum toxin types E and F are produced as only approximately 300 kD complexes. The complexes (i.e. molecular weight greater than about 150 kD) are believed to contain a non-toxin hemaglutinin protein and a non-toxin and non-toxic nonhemaglutinin protein. These two non-toxin proteins (which along with the botulinum toxin molecule comprise the relevant neurotoxin complex) may act to provide stability against denaturation to the botulinum toxin molecule and protection against digestive acids when toxin is ingested. Additionally, it is possible that the larger (greater than about 150 kD molecular weight) botulinum toxin complexes may result in a slower rate of diffusion of the botulinum toxin away from a site of intramuscular injection of a botulinum toxin complex.
In vitro studies have indicated that botulinum toxin inhibits potassium cation induced release of both acetylcholine and norepinephrine from primary cell cultures of brainstem tissue. Additionally, it has been reported that botulinum toxin inhibits the evoked release of both glycine and glutamate in primary cultures of spinal cord neurons and that in brain synaptosome preparations botulinum toxin inhibits the release of each of the neurotransmitters acetylcholine, dopamine, norepinephrine (Habermann E., et al., Tetanus Toxin and Botulinum A and C Neurotoxins Inhibit Noradrenaline Release From Cultured Mouse Brain, J Neurochem 51 (2); 522-527:1988) CGRP, substance P and glutamate (Sanchez-Prieto, J., et al., Botulinum Toxin A Blocks Glutamate Exocytosis From Guinea Pig Cerebral Cortical Synaptosomes, Eur J. Biochem 165; 675-681:1987. Thus, when adequate concentrations are used, stimulus-evoked release of most neurotransmitters is blocked by botulinum toxin. See e.g. Pearce, L. B., Pharmacologic Characterization of Botulinum Toxin For Basic Science and Medicine, Toxicon 35(9); 1373-1412 at 1393; Bigalke H., et al., Botulinum A Neurotoxin Inhibits Non-Cholinergic Synaptic Transmission in Mouse Spinal Cord Neurons in Culture, Brain Research 360; 318-324:1985; Habermann E., Inhibition by Tetanus and Botulinum A Toxin of the release of [3H]Noradrenaline and [3H]GABA From Rat Brain Homogenate, Experientia 44; 224-226:1988, Bigalke H., et al., Tetanus Toxin and Botulinum A Toxin Inhibit Release and Uptake of Various Transmitters, as Studied with Particulate Preparations From Rat Brain and Spinal Cord, Naunyn-Schmiedeberg's Arch Pharmacol 316; 244-251:1981, and; Jankovic J. et al., Therapy With Botulinum Toxin, Marcel Dekker, Inc., (1994), page 5.
Botulinum toxin type A can be obtained by establishing and growing cultures of Clostridium botulinum in a fermenter and then harvesting and purifying the fermented mixture in accordance with known procedures. All the botulinum toxin serotypes are initially synthesized as inactive single chain proteins which must be cleaved or nicked by proteases to become neuroactive. The bacterial strains that make botulinum toxin serotypes A and G possess endogenous proteases and serotypes A and G can therefore be recovered from bacterial cultures in predominantly their active form. In contrast, botulinum toxin serotypes C1, D and E are synthesized by nonproteolytic strains and are therefore typically unactivated when recovered from culture. Serotypes B and F are produced by both proteolytic and nonproteolytic strains and therefore can be recovered in either the active or inactive form. However, even the proteolytic strains that produce, for example, the botulinum toxin type B serotype only cleave a portion of the toxin produced. The exact proportion of nicked to unnicked molecules depends on the length of incubation and the temperature of the culture. Therefore, a certain percentage of any preparation of, for example, the botulinum toxin type B toxin is likely to be inactive, possibly accounting for the known significantly lower potency of botulinum toxin type B as compared to botulinum toxin type A. The presence of inactive botulinum toxin molecules in a clinical preparation will contribute to the overall protein load of the preparation, which has been linked to increased antigenicity, without contributing to its clinical efficacy. Additionally, it is known that botulinum toxin type B has, upon intramuscular injection, a shorter duration of activity and is also less potent than botulinum toxin type A at the same dose level.
High quality crystalline botulinum toxin type A can be produced from the Hall A strain of Clostridium botulinum with characteristics of ≧3×107 U/mg, an A260/A278 of less than 0.60 and a distinct pattern of banding on gel electrophoresis. The known Shantz process can be used to obtain crystalline botulinum toxin type A, as set forth in Shantz, E. J., et al, Properties and use of Botulinum toxin and Other Microbial Neurotoxins in Medicine, Microbiol Rev. 56; 80-99:1992. Generally, the botulinum toxin type A complex can be isolated and purified from an anaerobic fermentation by cultivating Clostridium botulinum type A in a suitable medium. The known process can also be used, upon separation out of the non-toxin proteins, to obtain pure botulinum toxins, such as for example: purified botulinum toxin type A with an approximately 150 kD molecular weight with a specific potency of 1-2×108 LD50 U/mg or greater; purified botulinum toxin type B with an approximately 156 kD molecular weight with a specific potency of 1-2×108 LD50 U/mg or greater, and; purified botulinum toxin type F with an approximately 155 kD molecular weight with a specific potency of 1-2×107 LD50 U/mg or greater.
Botulinum toxins and/or botulinum toxin complexes can be obtained from List Biological Laboratories, Inc., Campbell, Calif.; the Centre for Applied Microbiology and Research, Porton Down, U.K.; Wako (Osaka, Japan), Metabiologics (Madison, Wis.) as well as from Sigma Chemicals of St Louis, Mo. Pure botulinum toxin can also be used to prepare a pharmaceutical composition.
As with enzymes generally, the biological activities of the botulinum toxins (which are intracellular peptidases) is dependant, at least in part, upon their three dimensional conformation. Thus, botulinum toxin type A is detoxified by heat, various chemicals surface stretching and surface drying. Additionally, it is known that dilution of the toxin complex obtained by the known culturing, fermentation and purification to the much, much lower toxin concentrations used for pharmaceutical composition formulation results in rapid detoxification of the toxin unless a suitable stabilizing agent is present. Dilution of the toxin from milligram quantities to a solution containing nanograms per milliliter presents significant difficulties because of the rapid loss of specific toxicity upon such great dilution. Since the toxin may be used months or years after the toxin containing pharmaceutical composition is formulated, the toxin can stabilized with a stabilizing agent such as albumin and gelatin.
A commercially available botulinum toxin containing pharmaceutical composition is sold under the trademark BOTOX® (available from Allergan, Inc., of Irvine, Calif.). BOTOX® consists of a purified botulinum toxin type A complex, albumin and sodium chloride packaged in sterile, vacuum-dried form. The botulinum toxin type A is made from a culture of the Hall strain of Clostridium botulinum grown in a medium containing N-Z amine and yeast extract. The botulinum toxin type A complex is purified from the culture solution by a series of acid precipitations to a crystalline complex consisting of the active high molecular weight toxin protein and an associated hemagglutinin protein. The crystalline complex is re-dissolved in a solution containing saline and albumin and sterile filtered (0.2 microns) prior to vacuum-drying. The vacuum-dried product is stored in a freezer at or below −5° C. BOTOX® can be reconstituted with sterile, non-preserved saline prior to intramuscular injection. Each vial of BOTOX® contains about 100 units (U) of Clostridium botulinum toxin type A purified neurotoxin complex, 0.5 milligrams of human serum albumin and 0.9 milligrams of sodium chloride in a sterile, vacuum-dried form without a preservative.
To reconstitute vacuum-dried BOTOX®, sterile normal saline without a preservative; (0.9% Sodium Chloride Injection) is used by drawing up the proper amount of diluent in the appropriate size syringe. Since BOTOX® may be denatured by bubbling or similar violent agitation, the diluent is gently injected into the vial. For sterility reasons BOTOX® is preferably administered within four hours after the vial is removed from the freezer and reconstituted. During these four hours, reconstituted BOTOX® can be stored in a refrigerator at about 2° C. to about 8° C. Reconstituted, refrigerated BOTOX® has been reported to retain its potency for at least about two weeks. Sloop, Neurology, 48:249-53:1997.
It has been reported that botulinum toxin type A has been used in clinical settings as follows:
(1) about 75-125 units of BOTOX® per intramuscular injection (multiple muscles) to treat cervical dystonia;
(2) 5-10 units of BOTOX® per intramuscular injection to treat glabellar lines (brow furrows) (5 units injected intramuscularly into the procerus muscle and 10 units injected intramuscularly into each corrugator supercilii muscle);
(3) about 30-80 units of BOTOX® to treat constipation by intrasphincter injection of the puborectalis muscle;
(4) about 1-5 units per muscle of intramuscularly injected BOTOX® to treat blepharospasm by injecting the lateral pre-tarsal orbicularis oculi muscle of the upper lid and the lateral pre-tarsal orbicularis oculi of the lower lid.
(5) to treat strabismus, extraocular muscles have been injected intramuscularly with between about 1-5 units of BOTOX®, the amount injected varying based upon both the size of the muscle to be injected and the extent of muscle paralysis desired (i.e. amount of diopter correction desired).(6) to treat upper limb spasticity following stroke by intramuscular injections of BOTOX® into five different upper limb flexor muscles, as follows:(a) flexor digitorum profundus: 7.5 U to 30 U(b) flexor digitorum sublimus: 7.5 U to 30 U(c) flexor carpi ulnaris: 10 U to 40 U(d) flexor carpi radialis: 15 U to 60 U(e) biceps brachii: 50 U to 200 U. Each of the five indicated muscles has been injected at the same treatment session, so that the patient receives from 90 U to 360 U of upper limb flexor muscle BOTOX® by intramuscular injection at each treatment session.(7) to treat migraine, pericranial injected (injected symmetrically into glabellar, frontalis and temporalis muscles) injection of 25 U of BOTOX® has showed significant benefit as a prophylactic treatment of migraine compared to vehicle as measured by decreased measures of migraine frequency, maximal severity, associated vomiting and acute medication use over the three month period following the 25 U injection.
Additionally, intramuscular botulinum toxin has been used in the treatment of tremor in patients with Parkinson's disease, although it has been reported that results have not been impressive. Marjama-Jyons, J., et al., Tremor-Predominant Parkinson's Disease, Drugs & Aging 16(4); 273-278:2000.
It is known that botulinum toxin type A can have an efficacy for up to 12 months (European J. Neurology 6 (Supp 4): S111-S1150:1999), and in some circumstances for as long as 27 months, when used to treat glands, such as in the treatment of hyperhydrosis. See e.g. Bushara K., Botulinum toxin and rhinorrhea, Otolaryngol Head Neck Surg 1996; 114(3):507, and The Laryngoscope 109:1344-1346:1999. However, the usual duration of an intramuscular injection of Botox® is typically about 3 to 4 months.
The success of botulinum toxin type A to treat a variety of clinical conditions has led to interest in other botulinum toxin serotypes. Two commercially available botulinum type A preparations for us in humans are BOTOX® available from Allergan, Inc., of Irvine Calif., and DYSPORT® available from Beaufour Ipsen, Porton Down, England. A botulinum toxin type B preparation (MYOBLOC®) is available from Elan Pharmaceuticals of San Francisco, Calif.
In addition to having pharmacologic actions at the peripheral location, botulinum toxins may also have inhibitory effects in the central nervous system. Work by Weigand et al, Naunyn-Schmiedeberg's Arch. Pharmacol. 1976; 292, 161-165, and Habermann, Naunyn-Schmiedeberg's Arch. Pharmacol. 1974; 281, 47-56 showed that botulinum toxin is able to ascend to the spinal area by retrograde transport. As such, a botulinum toxin injected at a peripheral location, for example intramuscularly, may be retrograde transported to the spinal cord.
U.S. Pat. No. 5,989,545 discloses that a modified clostridial neurotoxin or fragment thereof, preferably a botulinum toxin, chemically conjugated or recombinantly fused to a particular targeting moiety can be used to treat pain by administration of the agent to the spinal cord.
It has been reported that use of a botulinum toxin to treat various spasmodic muscle conditions can result in reduced depression and anxiety, as the muscle spasm is reduced. Murry T., et al., Spasmodic dysphonia; emotional status and botulinum toxin treatment, Arch Otolaryngol 1994 March; 120(3): 310-316; Jahanshahi M., et al., Psychological functioning before and after treatment of torticollis with botulinum toxin, J Neurol Neurosurg Psychiatry 1992; 55(3): 229-231. Additionally, German patent application DE 101 50 415 A1 discusses intramuscular injection of a botulinum toxin to treat depression and related affective disorders.
A botulinum toxin has also been proposed for or has been used to treat skin wounds (U.S. Pat. No. 6,447,787), various autonomic nerve dysfunctions (U.S. Pat. No. 5,766,605), post-operative pain and visceral pain (U.S. Pat. No. 6,464,986), neuralgia pain (U.S. patent application Ser. No. 630,587), hair growth and hair retention (U.S. Pat. No. 6,299,893), dental related ailments (U.S. provisional patent application Ser. No. 60/418,789), fibromyalgia (U.S. Pat. No. 6,623,742), various skin disorders (U.S. patent application Ser. No. 10/731,973), motion sickness (U.S. patent application Ser. No. 752,869), psoriasis and dermatitis (U.S. Pat. No. 5,670,484), injured muscles (U.S. Pat. No. 6,423,319) various cancers (U.S. Pat. No. 6,139,845), smooth muscle disorders (U.S. Pat. No. 5,437,291), down turned mouth corners (U.S. Pat. No. 6,358,917), nerve entrapment syndromes (U.S. patent application 2003 0224019), various impulse disorders (U.S. patent application Ser. No. 423,380), acne (WO 03/011333) and neurogenic inflammation (U.S. Pat. No. 6,063,768). Controlled release toxin implants are known (see e.g. U.S. Pat. Nos. 6,306,423 and 6,312,708) as is transdermal botulinum toxin administration (U.S. patent application Ser. No. 10/194,805).
Botulinum toxin type A has been used to treat epilepsia partialis continua, a type of focal motor epilepsy. Bhattacharya K., et al., Novel uses of botulinum toxin type A: two case reports, Mov Disord 2000; 15(Suppl 2):51-52.
Additionally, a botulinum toxin may have an effect to reduce induced inflammatory pain in a rat formalin model. Aoki K., et al, Mechanisms of the antinociceptive effect of subcutaneous Botox: Inhibition of peripheral and central nociceptive processing, Cephalalgia 2003 September; 23(7):649. Furthermore, it has been reported that botulinum toxin nerve blockage can cause a reduction of epidermal thickness. Li Y, et al., Sensory and motor denervation influences epidermal thickness in rat foot glabrous skin, Exp Neurol 1997; 147:452-462 (see page 459). Finally, it is known to administer a botulinum toxin to the foot to treat excessive foot sweating (Katsambas A., et al., Cutaneous diseases of the foot: Unapproved treatments, Clin Dermatol 2002 November-December; 20(6):689-699; Sevim, S., et al., Botulinum toxin-A therapy for palmar and plantar hyperhidrosis, Acta Neurol Belg 2002 December; 102(4):167-70), spastic toes (Suputtitada, A., Local botulinum toxin type A injections in the treatment of spastic toes, Am J Phys Med Rehabil 2002 October; 81(10):770-5), idiopathic toe walking (Tacks, L., et al., Idiopathic toe walking: Treatment with botulinum toxin A injection, Dev Med Child Neurol 2002; 44(Suppl 91):6), and foot dystonia (Rogers J., et al., Injections of botulinum toxin A in foot dystonia, Neurology 1993 April; 43(4 Suppl 2)).
Furthermore, a botulinum toxin has been used to treat many types of headache, such as tension headache, (see eg U.S. Pat. No. 6,458,365), migraine headache pain (see eg U.S. Pat. No. 5,714,468), and sinus headache (see U.S. Pat. No. 6,838,434). When a patient who has a headache or who has a propensity to have a headache is administered a botulinum toxin (to treat the headache and/or to prevent occurrence of a headache) the patient can respond to the administered botulinum toxin in varying ways, meaning that the botulinum toxin can be totally effective, partially effective or not effective at all to treat the headache and/or to prevent occurrence of a headache. Clearly it could benefit patient care, conserve physician time and prevent unnecessary use of a pharmaceutical if it could be determined prior to administration of a botulinum toxin if use of the botulinum for a particular patient will be effective to treat a headache and/or to prevent development of a headache.
What is needed therefore is a method for determining prior to administration of a botulinum toxin to a patient who has a headache or who has a propensity to have a headache, if the botulinum toxin will be effective in that patient.